There has been developed a robot which operates communicating with humans. Such a robot is required to have a function of recognizing surrounding objects. If information such as an object image is provided to a robot in advance, an object can be recognized with a predetermined degree of accuracy from visual information. However, it is not practical to provide the robot in advance with information of all objects that may lie around the robot. Therefore, there is a need that the robot has a function of identifying an unknown object, as well as a function of recognizing a known object. Such capability makes it possible for the robot to cope with the unknown object by identifying the unknown object.
FIG. 1 is a diagram illustrating a robot and surrounding objects. The robot has data for the objects other than a vase and can recognize the objects. The robot has no data about the vase. In this case, if the robot can identify the vase as an unknown object, the robot can communicate with humans, based on the identification. For example, when a human orders the robot to “Please bring the vase.”, the robot may identify the vase as an unknown object and then ask the human “Is this the vase?” pointing to the vase, an unknown object.
Conventionally, a method for forming a concept of an object using multimodal information of an auditory sense, a visual sense, and a tactile sense (Non-Patent Literature 1) and a lexical acquisition apparatus for storing an unknown name during conversation (Patent Literature 1) have been developed. However, no apparatus and method for identifying an unknown object has been developed.